The analysts Mark May and Hao Yan wrote: "While the recent redesign of [Snap's] flagship app could produce positive long-term benefits, [there is a] significant jump in negative app reviews since the redesign was pushed out a few weeks, which could result in a decline in users and user engagement, and could negatively impact financial results."

Citi warned that, in the longer term, the app's redesign could "benefit monetization near term despite some overall user and usage headwinds, if time spent on commercial content rises."

In other words, the redesign could be successful and persuade lots more people to spend lots more time on Snapchat. That, in turn, would boost ad spend. Snap's slowdown in hiring may also turn out to be good news for its bottom line.